Connect with TRB

EFFECTIVE WARNING DEVICES FOR PARKED/DISABLED VEHICLES

The report reviews an experiment undertaken to examine the effectiveness of three different warning device configurations for alerting motorists to the presence of an unattended parked/disabled vehicle (PDV) at the roadside and the need for caution in passing it by. This data collected and analyzed were essentially the speed profiles of passing (random) motorists as they approached and passed by the PDV location in a rural two-lane situation. The three configurations included four-way flashers used on the PDV, and the four-way flashers used in conjunction with warning triangles deployed in two different fashions (i.e., all behind PDV; one ahead, two behind) around the PDV. For comparison purposes, data were also collected when the PDV was not present (a base condition). Data were collected during the day and night, or near and far lane vehicles, with the PDV at different offsets from the pavement edge, and on opposed and unopposed vehicles. A limited number of data were also collected during adverse weather/visibility conditions (night, rain, wet pavement).

Supplemental Notes:

See also Executive Summary, PB81-156929. Prepared in cooperation with Maine Dept. of Transportation Bangor. Materials and Research Div.